1. Field of the Invention
Aspects of the present invention relate generally to a mask defect testing apparatus, and more specifically, to a mask defect testing apparatus that tests whether a mask used for a display panel manufacturing process is defective or not.
2. Description of the Related Art
Display panel manufacturing processes generally employ various kinds of masks. For example, a metal mask is used for precise processes. However, in some cases defects can occur, such as where fine foreign materials are attached to the metal mask, resulting in damage to the patterns in the mask. These defects can cause a large loss in all the manufacturing processes using the corresponding metal mask.
As a result, the presence of a defect of the metal mask should be regularly tested before or after the metal mask is used. One method of testing the defect of the metal mask involves fixing the metal mask to be tested to a jig and then testing the defect of the fixed metal mask using a test mask. At this time, as a camera more closely approaches a metal mask to be tested, the ability to detect damage to the pattern and foreign materials is improved.
However, since a clamp of a jig fixing an edge of the metal mask generally has a structure that protrudes upward, the test camera can only approach the metal mask fixed to the jig within a range that does not collide with the jig. In other words, due to the structure of the jig fixing the metal mask, the camera is limited in approaching the metal mask to be tested or testing an edge portion of the metal mask. Therefore, the presence of a defect of the metal mask is not precisely and stably tested.